The present invention is generally related to adjustable tillers for motor vehicles. More particularly, the present invention is related to a tiller, for a motorized scooters for persons of limited mobility, the position of which is continuously adjustable.
A scooter is a motorized, usually battery electric, vehicle, typically for a person who is able to walk but is not able to walk long distances. For psychological reasons, scooters are designed to look more like a motor-scooter than a wheelchair. Typically, the scooter has a pair of wheels driven by a motor at the rear, and one or two steerable wheels at the front controlled by a tiller. The tiller typically consists of a generally upright column with a pair of handlebars at the top. A seat for the user is positioned above the motor. Between the motor and the tiller is a footplate for the user""s feet. The distance from the base of the tiller to the seated user is thus effectively fixed. However, different users have arms of different lengths, so it is desirable for the position of the handlebars to be adjustable towards and away from the user. Previous tiller adjustment systems allow the tiller to be pivoted forwards and backwards, but typically allow the tiller to be set only at certain fixed positions. Practical considerations in the design and construction of the adjustment systems result in a substantial separation between adjacent fixed positions. The separation is amplified because the adjustment system is typically at the base of the tiller, near its axis of pivoting, while the handlebars are at the top of the tiller, much further from the axis. As a result, previous adjustable tillers could not always be set to the optimum position, especially for a user of limited agility.
It is an object of the invention to provide a scooter with a tiller that can be adjusted easily and steplessly, but that remains securely in the position to which it has been adjusted.
According to one aspect of the invention, a motorized vehicle comprises at least one steerable wheel, and a member mounted rotatably about an axis and operatively connected to the at least one steerable wheel such that rotation of the rotatably mounted member about that axis causes steering of the at least one steerable wheel. A pivot block with a pair of lubricating plates of low-friction material on either side is mounted on a free end of the rotatably mounted member. A steering member to rotate the rotatably mounted member comprises a pair of forks straddling the pivot block and bearing on the lubricating plates. A pivot pin, about which the steering member is pivotable relative to the rotatably mounted member, passes through the forks and the pivot block transverse to the axis of rotation of the rotatably mounted member. A strut of variable length is so connected to the steering member and to the mounting block that pivoting of the steering member requires a change in the length of the strut. A clamp locks the strut at any length corresponding to a desired pivotal position of the steering member.
According to another aspect of the invention, a pivot block has a bore for a pivot pin passing through the pivot block, and has a pair of recesses surrounding the ends of the bore on either side of the pivot block. A pair of lubricating plates of low-friction material are fitted into the recesses. The lubricating plates define bearing surfaces for a pair of forks disposed either side of the pivot block and pivoting about a pivot pin positioned in the bore.